(Photo: Tomas Munita / The New York Times)Washington - Syrian insurgents fighting to unseat President Bashar Assad face a growing list of accusations that they’ve carried out executions and torture, muddying the Western narrative of a heroic resistance force struggling against a vicious regime.

The issue of rebel conduct has come to the forefront this month largely because of a video posted online showing the aftermath of apparent executions of pro-Assad militiamen during the rebels’ capture of an intelligence center in Aleppo, Syria’s largest city.

A reporter for the Turkish newspaper Milliyet witnessed the incident Tuesday and confirmed in a first-person account the circumstances of the killings: More than a dozen men were captured alive and then summarily executed in what advocacy group Human Rights Watch called an apparent “war crime.”

The men “were forced into a building, then brought before a court of the Free Syrian Army on the back of a pickup truck, after which they were lined up and shot at lightning speed,” the Milliyet reporter wrote.

The incident doesn’t appear to be isolated, either. A McClatchy reporter traveling with a unit of the Free Syrian Army was told that rebels had captured about 45 Assad loyalists in fighting in Al Tal, north of Damascus. Asked later what had become of the prisoners, a rebel said eight had been executed, 25 had been released and the rest were being held in hopes of a future prisoner exchange.

This week, a rebel commander in Damascus said that over the months his unit had executed perhaps 150 people it had detained on suspicion of being pro-Assad informants.

The Agence France-Presse news service, meanwhile, cited a top Iraqi security official in a report July 19 describing the rebels’ takeover of a border outpost. According to the official in the report, “they executed 22 soldiers in front of the eyes of Iraqi soldiers.”

Meanwhile, the so-called Daoud Battalion, a rebel force that operates in Jebel al Zawiyah in northern Syria, used its captives and suspected spies in an “ingenious” form of vehicle bombings against regime targets, according to a July 25 report on rebel groups by the Institute for the Study of War, a Washington-based think-tank that has made a specialty of studying the Syrian rebel movement.

The rebels put the prisoners in cars rigged with explosives and then remotely detonated the bombs when the vehicles approached government checkpoints.

"In videos of these attacks, the group has been careful to note that despite their appearance, they are not ’martyrdom operations,’" the report said, a reference to suicide attacks by its own members.

Taken as a whole, such incidents show the depth of the uprising’s evolution in 17 months from a protest movement against dictatorship to an all-out civil war, with both sides committing what ultimately may be viewed as war crimes.

“We’re going to face retaliation and revenge at the end because the numbers of those being killed is huge,” said Mohammad Abdallah, head of the new Syria Justice and Accountability Center, a partly U.S.-funded center for documenting atrocities. “The rebels, the protesters, maintained remarkable self-control at the beginning, but after that, the (regime’s) killing approached a level you cannot really tolerate, and everyone has the right to defend themselves in the end.”

Even the rebels’ U.S. supporters appear to be more cautious in their statements after a series of hits to the opposition forces’ credibility: purported videos of regime crimes that were revealed as fakes, exaggerations in reports of mass killing by government forces, the spread of militant Islamists in rebel ranks, U.N. claims of cease-fire violations and, now, potential atrocities such as prisoner executions.

“We strongly condemn summary executions by either side in Syria. We condemn actions like that,” White House Press Secretary Jay Carney told reporters this week. He quickly added, however, that it was Assad’s forces “that have perpetrated the overwhelming amount of violence in Syria.”

Earlier this week, fighters in a rebel-held suburb of Damascus stopped and interrogated three men driving through the area on suspicion that they were government informants. After being held for several hours, the men were released, having proved their identity to the rebels’ satisfaction.

Other suspects haven’t been so lucky, explained a rebel commander in Damascus who uses the nom de guerre Abu Abdullah.

“We have had a big problem here with informers,” he said. “If a man is accused of being an informer, he is judged by the military council. Then he is either executed or released. In general, about two out of three are executed.”

Abu Abdullah said that the council had ordered the executions of some 150 men since the beginning of the conflict, but that the rate had declined as the rebels feel the neighborhood is “cleaned” of pro-regime elements.

“In the beginning, we would execute 10 or 15 men a week,” he said. “Now it’s closer to one every 10 or 20 days.”

At least some rebel elements appear keenly aware that their moral high ground is in danger of being challenged and have issued statements in recent days vowing to abide by international conventions governing battlefield conduct. However, the Free Syrian Army remains only loosely organized, with no true central command, and it’s impossible to tell which – if any – units are enforcing such orders.

In one video, posted Monday on YouTube, a self-proclaimed representative of the Free Syrian Army read a statement announcing that, in response to international concerns, units would adhere to the Geneva Convention’s guidelines for the treatment of prisoners and would guarantee its captives food, medical attention and holding areas away from active combat zones. The rebel spokesman also invited Red Cross workers to inspect their detention facilities.

“We tell everyone that we are revolting against a barbarous regime that always tortured and treated detainees and arrestees in brutal ways that led to the deaths of many,” the rebel says in the video. “That’s why we can never adopt the behavior of that very entity that we are revolting against.”

International humanitarian organizations and conflict monitoring agencies have become more vocal in criticizing rebel forces for battlefield transgressions, warning them against tit-for-tat violence that would only fuel the civil strife.

One, the International Crisis Group, a nonprofit monitor of global conflicts, called on the rebels to assume responsibility for halting revenge killings.

“The regime almost certainly will not change its ways, so the burden must fall on the opposition to do what – given the immensity of its suffering – must seem an improbable undertaking: seriously address the phenomena of retaliatory violence, sectarian killings and creeping fundamentalism within its ranks,” the group in a report released Wednesday titled “Syria’s Mutating Conflict.”

The group also recommended that the opposition rethink the goal of total regime change and focus on rehabilitating current institutions. To reassure Assad’s minority Alawite sect, so far the backbone of his support, and other regime loyalists, the opposition should “come up with forward-looking proposals on transitional justice, accountability and amnesty,” the report said.

(Photo: Tomas Munita / The New York Times)Washington - Syrian insurgents fighting to unseat President Bashar Assad face a growing list of accusations that they’ve carried out executions and torture, muddying the Western narrative of a heroic resistance force struggling against a vicious regime.

The issue of rebel conduct has come to the forefront this month largely because of a video posted online showing the aftermath of apparent executions of pro-Assad militiamen during the rebels’ capture of an intelligence center in Aleppo, Syria’s largest city.

A reporter for the Turkish newspaper Milliyet witnessed the incident Tuesday and confirmed in a first-person account the circumstances of the killings: More than a dozen men were captured alive and then summarily executed in what advocacy group Human Rights Watch called an apparent “war crime.”

The men “were forced into a building, then brought before a court of the Free Syrian Army on the back of a pickup truck, after which they were lined up and shot at lightning speed,” the Milliyet reporter wrote.

The incident doesn’t appear to be isolated, either. A McClatchy reporter traveling with a unit of the Free Syrian Army was told that rebels had captured about 45 Assad loyalists in fighting in Al Tal, north of Damascus. Asked later what had become of the prisoners, a rebel said eight had been executed, 25 had been released and the rest were being held in hopes of a future prisoner exchange.

This week, a rebel commander in Damascus said that over the months his unit had executed perhaps 150 people it had detained on suspicion of being pro-Assad informants.

The Agence France-Presse news service, meanwhile, cited a top Iraqi security official in a report July 19 describing the rebels’ takeover of a border outpost. According to the official in the report, “they executed 22 soldiers in front of the eyes of Iraqi soldiers.”

Meanwhile, the so-called Daoud Battalion, a rebel force that operates in Jebel al Zawiyah in northern Syria, used its captives and suspected spies in an “ingenious” form of vehicle bombings against regime targets, according to a July 25 report on rebel groups by the Institute for the Study of War, a Washington-based think-tank that has made a specialty of studying the Syrian rebel movement.

The rebels put the prisoners in cars rigged with explosives and then remotely detonated the bombs when the vehicles approached government checkpoints.

"In videos of these attacks, the group has been careful to note that despite their appearance, they are not ’martyrdom operations,’" the report said, a reference to suicide attacks by its own members.

Taken as a whole, such incidents show the depth of the uprising’s evolution in 17 months from a protest movement against dictatorship to an all-out civil war, with both sides committing what ultimately may be viewed as war crimes.

“We’re going to face retaliation and revenge at the end because the numbers of those being killed is huge,” said Mohammad Abdallah, head of the new Syria Justice and Accountability Center, a partly U.S.-funded center for documenting atrocities. “The rebels, the protesters, maintained remarkable self-control at the beginning, but after that, the (regime’s) killing approached a level you cannot really tolerate, and everyone has the right to defend themselves in the end.”

Even the rebels’ U.S. supporters appear to be more cautious in their statements after a series of hits to the opposition forces’ credibility: purported videos of regime crimes that were revealed as fakes, exaggerations in reports of mass killing by government forces, the spread of militant Islamists in rebel ranks, U.N. claims of cease-fire violations and, now, potential atrocities such as prisoner executions.

“We strongly condemn summary executions by either side in Syria. We condemn actions like that,” White House Press Secretary Jay Carney told reporters this week. He quickly added, however, that it was Assad’s forces “that have perpetrated the overwhelming amount of violence in Syria.”

Earlier this week, fighters in a rebel-held suburb of Damascus stopped and interrogated three men driving through the area on suspicion that they were government informants. After being held for several hours, the men were released, having proved their identity to the rebels’ satisfaction.

Other suspects haven’t been so lucky, explained a rebel commander in Damascus who uses the nom de guerre Abu Abdullah.

“We have had a big problem here with informers,” he said. “If a man is accused of being an informer, he is judged by the military council. Then he is either executed or released. In general, about two out of three are executed.”

Abu Abdullah said that the council had ordered the executions of some 150 men since the beginning of the conflict, but that the rate had declined as the rebels feel the neighborhood is “cleaned” of pro-regime elements.

“In the beginning, we would execute 10 or 15 men a week,” he said. “Now it’s closer to one every 10 or 20 days.”

At least some rebel elements appear keenly aware that their moral high ground is in danger of being challenged and have issued statements in recent days vowing to abide by international conventions governing battlefield conduct. However, the Free Syrian Army remains only loosely organized, with no true central command, and it’s impossible to tell which – if any – units are enforcing such orders.

In one video, posted Monday on YouTube, a self-proclaimed representative of the Free Syrian Army read a statement announcing that, in response to international concerns, units would adhere to the Geneva Convention’s guidelines for the treatment of prisoners and would guarantee its captives food, medical attention and holding areas away from active combat zones. The rebel spokesman also invited Red Cross workers to inspect their detention facilities.

“We tell everyone that we are revolting against a barbarous regime that always tortured and treated detainees and arrestees in brutal ways that led to the deaths of many,” the rebel says in the video. “That’s why we can never adopt the behavior of that very entity that we are revolting against.”

International humanitarian organizations and conflict monitoring agencies have become more vocal in criticizing rebel forces for battlefield transgressions, warning them against tit-for-tat violence that would only fuel the civil strife.

One, the International Crisis Group, a nonprofit monitor of global conflicts, called on the rebels to assume responsibility for halting revenge killings.

“The regime almost certainly will not change its ways, so the burden must fall on the opposition to do what – given the immensity of its suffering – must seem an improbable undertaking: seriously address the phenomena of retaliatory violence, sectarian killings and creeping fundamentalism within its ranks,” the group in a report released Wednesday titled “Syria’s Mutating Conflict.”

The group also recommended that the opposition rethink the goal of total regime change and focus on rehabilitating current institutions. To reassure Assad’s minority Alawite sect, so far the backbone of his support, and other regime loyalists, the opposition should “come up with forward-looking proposals on transitional justice, accountability and amnesty,” the report said.